<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>
    const p = {
        then(){
            return {
                then(){
                    return {
                        then(){
                            return 100;
                        }
                    }
                }
            }
        }
    }
    const p1 =  p.then().then().then();
    console.log(p1);
</script>
</html>